Teeter terminal clamp

ABSTRACT

The teeter terminal clamp for removably securing the terminal portion of a single conductor or two conductors of the same or different diameter comprises a threaded shank having a head for rotating the shank, the head having an underhead surface with at least one, integrally-formed, substantially-circular or oval protrusion surrounding the shank and intermediate the inner and outer extremity of the underhead surface; a clamping plate substantially centrally apertured and assembled loosely and tiltably on the shank adjacent the head, the plate having on the side adjacent the head at least one, substantially-circular or oval recess complementing the shape of the protrusion whereby the extremity of the protrusion registers with an intermediate portion of the inner wall of the recess when the protrusion and recess are in registration, the plate also having on the other side conductor-engaging, anti-pullout surface irregularities; and means for retaining the plate on the shank adjacent the head.

United States Patent Gutshall July 3, 1973 TEETER TERMINAL CLAMP [57]ABSTRACT [75] Inventor; Ch -k E, G t h ll, S h b The teeter terminalclamp for removably securing the [1[ terminal portion of a singleconductor or two conductors of the same or different diameter comprisesa [73] Asslgnee: Elm Indusmes Rockford threaded shank having a head forrotating the shank,

22 Filed; Apt 1972 the head having an underhead surface with at leastone,

integrally-formed, substantially-circular or oval protru- [Zll Appl'241581 sion surrounding the shank and intermediate the inner and outerextremity of the underhead surface; a clamp- 52 us. Cl. 339/246, 339/95R s Plate Substantially Centrally apertured and assem- 51 int. Cl non-9/10 bled loosely and tiltably on the Shank adjacent the 581 Field ofSearch 339/95, 246, 263 head. the plate having on the side adjacent thehead at least one, substantially-circular or oval recess comple- [56 Refren g Cited menting the shape of the protrusion whereby the ex- UNITEDSTATES PATENTS tremity of the protrusion registers with an intermediateportion of the inner wall of the recess when the protrusion and recessare in registration, the plate also having Primary ExaminerJoseph H.McGlynn Attorney-Albert H. Pendleton, William J. Birmingham on the otherside conductor-engaging, anti-pullout surface irregularities; and meansfor retaining the plate on the shank adjacent the head.

13 Claims, 15 Drawing Figures PMENIEUJuL a ma FIG.I

FIG. 2

FIG. 5

FIG. 3

FIG. 4

memsum am 3.744.012

FIG. 6 4

1 TEETER TERMINAL CLAMP BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to terminal clamps of the threaded typewhich are employed to releasably secure the terminal portions ofelongated members such as electrical conductors to a workpiece or toeach other. More specifically, it relates to a threaded terminal clamphaving a clamping plate which teeters or tilts in order to accommodateand securely clamp either a single wire or two wires of the same ordifferent size and in the case of a pair of wires to apply approximatelyequal clamping loads to each wire.

While the present invention will be described with particular referenceto threaded terminal clamps specifically designed to cope with theproblem of clamping the terminal portions of two electrical conductorshaving different sizes or diameters, it should be understood that theinvention is not necessarily limited thereto.

The inventive concepts set forth herein can be readily adapted to copewith equal-load clamping problems associated with elongated members ingeneral, as those skilled in the art will recognize in the light of thepresent disclosure.

2. Description of the Prior Art .The art relating to terminal clamps forelectrical connectors is highly developed because of the long-existingneed for improved means for releasably securing electrical leads, bothsolid and stranded, wires, cables and other connectors to one anotherand to terminal posts. This need is dictated in part by the cost,inconvenience and obvious hazards, including shock, electrocution, fireand other destructive consequences which can occur if a hot lead becomesunintentionally and unknowingly unfastened. This need is reflected inpart in the establishment of various applicable performance standards byUnderwriters Laboratories, lnc. It is reflected in part in the patentart in this field, typical of a some of the prior art being U.S. Pat.Nos. 2,151,674,

2,304,711, 2,946,039, 3,050,706 and 3,509,517.

The need and the problems associated therewith are even more acute inconnection with clamps which must be readily releasable, yet highlysecure when fastening either one or two wires, including pairs of wiresof different diameters. Some of the prior art terminal clamps have beenspecifically designed to have the versatility of accommodating aplurality of electrical wires having different diameters butapproximately equal clamping loads. Various approaches include, forexample, clamping plates which teeter or rock relative to the shankaxis. To permit such teetering the aperture in the plate may beoversized or, at least, elongated in a direction generally perpendicularto the axis of the wires being accommodated. Some of the prior art patents relating to terminal clamps for accommodatng wires of differentsize include, for example, U.S. Pat. Nos. 3,081,507, 3,177,456,3,178,675, 3,191,140, 3,238,495 and 3,509,521.

Another problem which the piror art has attempted to solve is theinconvenience and cost of assembling the clamping devices on thethreaded fasteners at the job site, particularly when the terminalclamps are very small in size and require a high degree of fingerdexterity to install. A related problem arises when removing orunclampng the terminal clamp to temporarily release, remove or replacethe wires. The clamping plate may fall off the shank or even stick orotherwise remain attached to the wires which were clamped thereby.

To cope with these problems, terminal clamps have been fabricated withretaining shoulders or rings integrally formed on the shank itself.These retain the clamping plates on the shank so that the electricianhas a preassembled device available for use. lnaddition, the shoulderpositively lifts the plates from the wires as the shank is unthreaded.Prior art devices employing shoulders on the threaded shanks, althoughnot necessarily for retaining terminal clamps, include, for example,U.S. Pat. Nos. 2,192,322, 3,141,722, 3,205,473, 3,372,366 and 3,398,393.

Prior art teeter terminal clamps, however, have suffered from one ormore shortcomings. For example, some have been unduly complex, comprisea number of parts, are difficult to assemble or use or are quite costlyto manufacture. Some have to be assembled on the job or require animble-fingered person to apply. Some are structurally weakened byvirtue of the particular configuration required for the clampingfunction.

Some are lacking in performance characteristics and versatility,particularly in their ability to handle pairs of wires of differentdiameters with approximately equal holding power. Some do not retain theclamping plate prior to use, or fail to positively lift the clampingplate from tee wires when the clamp is unscrewed from the wires.

Some, particularly the peaked or rooftop types, are not well adapted tocope with stranded wire and lend themselves to flattening and relatedovertightening problems. The captured peak-type terminal clamp, whereinthe threads or retaining collar are rolled on or otherwise added to theshank after assembly of the plate'thereon, also have the additionaldisadvantage of an undesirably large space or gap along the shankbetween the undersurface of the head and the beginning of the threadedportion or collar.

It is to the solution of these and other problems to which the presentinvention is directed. This will be apparent from the following objects.

OBJECTS OF THE INVENTION It is therefore a general object of the presentinvention to provide an improved teeter terminal clamp overcoming manyof the shortcomings and disadvantages of prior art types. It is anothergeneral object to provide a low-cost, simplified teeter terminal clampwhich in certain embodiments comprises only two easy-to-manufacturecomponents. It is another general object to provide a preassembledteeter terminal clamp which can be quickly and conveniently secured orreleased and does not require special skills to utilize.

It is a more specific object to provide an improved teeter terminalclamp which can be interchangeably employed to releasably secure theterminal portions of a single wire or a pair of wires. It is anotherspecific object to provide a clamp which can releasably secure a pair ofwires of different sizes to one another or to a terminal post withsubstantially equal holding forces. It is another specific object toprovide a terminal clamp capable of meeting accepted standards forsecureness, pullout load and minimum torque at failure.

It is still another specific object to provide a teeter terminal clampcapable of coping with the problems peculiar to the clamping of strandedwire. It is still another specific object to cope with the problemspeculiar to peaked or rooftop clamps. It is still another specificobject to provide a teeter terminal clamp having a design which does notstructurally weaken the components.

These and other objects will become apparent as the description thereofproceeds.

SUMMARY OF THE INVENTION These objects are achieved by a teeter terminalclamp comprising a threaded shank having a head configured to receive atool for rotating the shank and an apertured clamping plate loosely andteeterably assembled and retained on the shank adjacent the head. Thehead has an underhead surface with at least one, integrally-formed,substantially-circular or oval protrusion, preferably generally V-shapedin cross sectional configuration, concentric with the shank axis andintermediate the inner and outer extremities of the underhead surface.

The clamping plate, which is preferably generally rectilinear, has onone side thereof at least one complementary substantially-circular oroval recess, also preferably V-shaped, but of larger diameter or largermajor or minor axes. The sizes of the protrusion and recess arecoordinated so that the extremity of the protrusion registers with theinner wall of the recess intermediate the outer and inner marginsthereof. The clamping plate on the other side also has wire-engaging,anti-slip surface irregularities, such as grooves or embossmerits,portions of which are at least in part transverse to the axes of thewires being retained.

In a particular embodiment the clamping plate is retained on thethreaded shank adjacent the head by an integrally-formed annular collar.The collar may be formed as disclosed, for example, in applicantscopending application Ser. No. 222,532, filed Feb. I, 1972.

As will be apparent from the drawings, the present invention lendsitself to a variety of embodiments. Some of these embodiments arespecifically adapted to meet particular needs. As used hereinafter, theterm substantially circular is intended to encompass elongated or ovalconfigurations as well. The concept is manifestly applicable to suchalternative configurations, as those skilled in the art will recognizein the light of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be moreclearly understood from the following detailed description of specificembodiments read in conjunction with the accompanying drawings, wherein:

FIG. I is a fragmentary elevation view, partly in section, showing on amagnified scale a preferred embodiment of the teeter terminal clampof'the present invention prior to threading it into a workpiece forclamping purposes;

FIG. 2 is similar to FIG. 1 except that it shows the teeter terminalclamp after being threaded into a workpiece for clamping two conductorsof different diameters;

FIG. 3 is an elevation view, on a slightly reduce scale as compared withFIGS. 1 and 2, of the headed blank prior to assembling the clampingplate and rolling the threads and retaining collar thereon;

FIG. 4 is a bottom plan view of the blank shown in FIG. 3;

FIG. 5 is a perspective view on an enlarged scale of the clamping plateof the embodiment of the present invention shown in FIG. 1;

FIG. 6 is an overhead plan view of the clamping plate of FIG. 5;

FIG. 7 is a sectional vie w along the line 77 of FIG.

FIG. 8 is a corner or diagonal view showng the side of the plate of FIG.6 in the same general direction as in FIG. 7;

FIG. 9 is a front elevation view of the plate of FIG.

FIG. 10 is a sectional view along the line 10 10 of FIG. 6;

FIG. 11 is a bottom plan view of the plate of FIG. 6;

FIG. 12 is an elevation view, partly in section, showing on a magnifiedscale another embodiment prior to tightening the threaded shank in aworkpiece;

FIG. 13 is similar to FIG. 12 and shows the disposition of thecomponents after tightening of the threaded shank;

FIG. 14 is a sectional view along the line l4l4 of FIG. 12; and

FIG. 15 is a sectional view along the line 15-15 of FIG. 12.

It should be understood that the drawings are not necessarily to scaleand that the embodiments are sometimes illustrated by graphic symbols,diagrammatic representations and fragmentary views. In certaininstances, details which are not necessary for an understanding of thepresent invention or which render other details difficult to perceivemay have been omitted. It should be understood, of course, that theinvention is not necessarily limited to the particular embodimentsillustrated herein.

DETAILED DESCRIPTION OF THE DRAWINGS, INCLUDING PREFERRED EMBODIMENTSReferring to FIG. 1, the teeter terminal clamp of the present inventioncomprises shank 10 having threads 12 along at least a portion of thelength thereof and generally circular head 14 at the upper terminal endas viewed in FIG. 1. Head 14 is slotted, as indicated by slot 16, toreceive the blade of the screwdriver for rotation of the shank wherebythe clamp may be tightened or loosened. Clamping plate 18 is loosely andteeterably assembled on shank 10 adjacent the undersurface 20 of head 14by means of retaining collar 22.

Referring to FIG. 2, the undersurface 20 of head 14 and the contactingupper surface of clamping plate 18 are complementarily designed, asdescribed in detail hereinafter, so as to clamp terminal ends ofconductors having different diameters, such as electrical leads 24 and26 which are being clamped to workpiece 28 in support structure 30.Despite the difference in diameters of leads 24 and 26, the clampingloads on these leads are substantially identical.

Referring to FIGS. 3 and 4, underhead surface 20 has at least one,integrally-formed, substantially circular and generally V-shapedprotrusion 32 concentric with the axis of shank l0 and intermediate theinner and outer extremities of underhead surface 20, that is, betweenthe juncture of the shank with the underhead surface and the outer edgethereof. As is apparent in FIG. 1, this protrusion registers with agenerally V- shaped, substantially circular recess in clamping plate 18whereby the geometry is such that the clamping plate self-adjusts ortilts to accommodate a single conductor lead or conductor leadsof'different diameters as protrayed in FIG. 2. Manifestly, the clampalso will accommodate two leads having the same diameter.

Referring to FIGS. 5-11, clamping plate 18 has a generally V-shaped,substantially circular recess 34 formed on the upper surface 36 thereofconcentric with the aperture defined by wall 38, which is centrallylocated relative to side walls 40, 41, 42 and 43. The aperture definedby wall 38 may be circular or oblong with major and minor axes. It isoversized relative to the shank so that plate 18 can teeter, rock ortilt relative to shank 10, and thus accommodate wires of differentdiameters. The minimum diameter or axis of aperture 38 is, however, lessthan the maximum diameter of collar 22 whereby plate 18 is retained onthe shank adjacent the head 14 by collar 22. The distance between theundersurface 20 of head 14 and collar 22, relative to the height orthickness of plate 18 is coordinated with the other variables so as notto restrict the desired degree of tiltability of plate 18.

When the protrusion 32 and recess 34 are concentrically aligned with theaxis of the shank and in contact, as portrayed in FIG. 1, the lowerextremity of protrusion 32 registers with the inner wall of recess 34between the upper and lower edges thereof. As shank is threaded into aworkpiece so as to clamp conductor leads, the lower surface of the clampcontacts the leads and, if uneven, tilts in a fashion whereby protrusion32 is caused to slip or slide down further into recess 34 on the highside and to ride upon the upper surface 36 of plate 18 on the low side.This action continues until the lower surfaces 52 of plate 18 (orembossments thereon) contact both leads. Further tightening appliesapproximately equal loads to the leads.

The lower surface 52 of clamping plate 18 has wireengaging, anti-slipsurface irregularities or embossments 44, 45, 46, 47, 48, 49, 50 and 51thereon which frictionally grip or otherwise imbed themselves into thewires to be clamped, thereby preventing the wires from being pulled outor shaken loose accidentally. At the same time the clamping action doesnot injure or materially reduce the current-carrying capacity of theleads. These irregularites or embossments are formed by stamping orotherwise forming complementary grooves 56, 58, 60, 62, 64, 66, 68 and70 in the upper surface 36 of plate 18. At the same time, the uppersurface portions 72, 74, 76 and 78 adjacent the four corners of plate 18are stamped or otherwise formed so as to direct the corners down-wardly,producing downward extremities 80, 82, 84 and 86, respectively.

The lower surface 52 also has a generally circular protrusion 88intersecting the embossments 44-51, which also assists in gripping thewires or leads to be clamped. Protrusion 88 is generally opposite recess34 and is preferably formed from the metal displaced to form the latter.It should be noted that in all instances the wire-gripping protrusionsor embossments 44-51 are disposed so that in the normal clampingoperation, at least one and normally two, embossments are at rightangles to the axes of the leads being clamped. This dispositionmaximizes the anti-pullout characteristic.

The underface or bottom of plate 18 adjacent the aperture may optionallybe debossed to produce the frustoconical configuration illustrated bythe dashed lines 53 in FIG. 10. This aids in the feeding of the plateprior to assembly thereof under certain circumstances.

Referring to the alternative embodiment of FIGS. 12-15, the teeterterminal clamp comprises shank having threads 102 along at least aportion of the length thereof and generally circular head 104 having aslot 106 therein to receive the blade of a screwdriver. U- shapedclamping plate 107 is loosely and teeterably assembled on shank 100adjacent the undersurface of head 104. It has depending walls 108 and109 and intermediate portion 110 with a centrally located aperturedefined by wall 111.

As in the case of the embodiment of FIGS. 1-l1, the

undersurface of head 104 and the contacting upper surface of U-shapedclamping plate 107 are complementarily designed to achieve the desiredequal clamping characteristics. Thus, regardless of any difference indiameter of conductor leads 112 and 114, they are clamped againstthreaded plate or nut 116 with substantially equal force.

The primary differences between this alternative embodiment and that ofFIGS. 1-11 lie in the fact that the undersurface of head 104 has adouble set of V-shaped substantially circular protrusions 118 and 120and clamping plate 107 has a complementary set of recesses 122 and 124.The relationship of the protrusions and recesses are the same as in theembodiment of FIGS. l-11 whereby equal clamping action is achieved onleads of different sizes, as depicted in FIG. 13. Thus, as protrusions118 and 120 slide into the recesses 122 and 124 on the left side of FIG.13, the protrusions on the right side are disposed radially inwardlyfrom the recesses. Thus, inner protrusion 120 on the right side bearsdirectly on the upper or major surface 110 of clamping plate 107.

The matching of protrusions and recesses in FIG. 13 is thusself-leveling. Inasmuch as the concentric head and clamping plate haveabutted each other with unyielding surfaces, the clamping forces on wireleads 112 and 114 are substantially equal.

As in the embodiment of FIGS. 1-11, the undersurface of clamping plate107 has surface irregularities, e.g., protrusions with intermediaterecesses, as best viewed in FIG. 15, which are designed to aid in thecoining or forming of the clamping plate and also impart anti-skid oranti-slip features to retain wire leads 112 and 114. They thus preventthe wire leads from being pulled out or shaken out accidentally withoutmaterially reducing the current-carrying capacity thereof.

In FIG. 15, it should be noted that the outer of surface protrusions 126and 128 has terminal portions 130, 132, 134 and 136 which are disposedat right angles to the normal disposition of the axes of the leads beingclamped, thus maximizing anti-pullout characteristics. The embossedrecesses, ridges, coinings, and/or formed members have the additionaladvantage of adding beam strength to the clamp so that more screwtension is permissible than would be the case if the structure were notsubjected to such metal forming operations.

EXAMPLE A teeter terminal clamp was fabricated substantially inaccordance with the embodiment of FIGS. 1-11 from heat-treatable zinc orcadmium-coated steel, the screw size being No. 6 with 32 threads perinch and a shank length of five-sixteenths inch. The resulting clamp wastested for torque, secureness and pullout characteristics, using bothsolid and stranded copper wire of various sizes, alone and incombination, in accordance with the requirements of UnderwritersLaboratories Standard 486. The torque tests were made 2. The clamp ofclaim 1 wherein said means for retaining said plate comprises anintegrally formed annular collar spaced from said head sufficiently toaccommodate said clamping plate in loose relationship prior using aspecial fixture adapted for same and stock PT to tightening.

terminals. The secureness and pullout tests were made 3. The clamp ofclaim 1 wherein said means for rewith a machine and fixture similar tothat shown in FIG. taining said plate comprises a nut threaded on said 1of Underwriters Laboratories Standard 486, again shank.

using stock PT terminals. The results are set forth in the 4. The clampof claim 3 wherein said plate has at following table: 10 least twoopposed appendages extending from margins Torque tests Wire underpressure Torque at plate (Awg.) failure Mode of failure secureness loadPullout load #12 solid 22 in. lbs Screw fractured at top of neck... 5lbs. for 2 hrs... 70 lbs. for 1 minute.

2#l2 solid... 35in. d 5 b .f0r2 hrs... Do.

#14 solid- 28 in. d for 2 hrs..- 60 lbs. for 1 minute.

2-#l4 solid. 36 in. for 2 hrs..- Do

l#12 solid. 35 in.

#16 solid 28 in. lbs ..do 2 lbs. #16 stranded.. 30 in.

#18 stranded.. 36 in. lbs do 2 lbs.

. for 2 hrs... 70 and (i0 lbs. for 1 minute.

for 1 hr...- 45 lbs. for 1 minute. for 1 hr...- Do.

for 1 hr...- 35 lbs. for 1 minute.

in all tests the teeter terminal clamps met the torque requirements ofUnderwriters Laboratories Standard 486, which is a minimum torque of 20inch pounds. The secureness and pullout tests were also successfullycompleted.

From the above description it is apparent that the objects of thepresent invention have been achieved. While only certain embodimentshave been set forth, alternative embodiments and various modificationswill be apparent from the above description to those skilled in the art.For example, the complementary protrusions and recesses on the headsurface and clamping plate upper surface, respectively, could undercertain circumstances be reversed. These and other alternatives areconsidered equivalents and within the spirit and scope of the presentinvention.

Having described the invention, what is claimed is:

l. A teeter terminal clamp for removably securing the terminal portionof at least one conductor comprising in combination:

a. a threaded shank having a head at one extremity and an entering endportion at the other extremity, said head being configured to cooperatewith a tool whereby the shank may be rotated into or out of a threadedaperture, said head having an underhead surface having at least one,integral, substantially V-shaped, substantially-circular protrusionconcentric with the shank axis and inter-mediate the inner and outerextremities of the underhead surface;

b. a clamping plate substantially centrally apertured to loosely andteeterably receive said shank, said plate having on one side thereof atleast one substantially V-shaped, substantially circular recesscomplementing said V-shaped protrusion but having a larger diameterwhereby the extremity of said V-shaped protrusion registers with theinner wall of said recess intermediate the two extremities thereof whensaid protrusion and said recess are concentrically aligned, said platehaving wireengaging, anti-slip surface irregularities on the oppositeside thereof; and

c. means for retaining said plate on said shank spacedly adjacent saidhead.

thereof away from said head and substantially aligned with the axis ofthe shank.

5. The clamp of claim 1 wherein said wire-engaging, anti-slip surfaceirregularities comprise grooves having at least portions disposed tointersect the wire being clamped substantially transversely.

6. The clamp of claim 1 wherein said wire-engaging, anti-slip surfaceirregularities comprise embossments disposed to intersect at least aportion of the wire being clamped substantially transversely.

7. The clamp of claim 1 wherein said clamping plate is substantiallyrectilinear.

8. The clamp of claim 7 wherein said wire-engaging, anti-slip surfaceirregularities comprise intersecting embossments spacedly adjacent eachof the four corners of the clamping plate substantially perpendicular tothe sides thereof.

9. The clamp of claim 8 wherein outer corner portions intermediate saidembossments are inclined away from said head.

10. The clamp of claim 1 including a plurality of said protrusions onthe underhead surface in spaced concentric relationship and a pluralityof complementary recesses in spaced concentric relationship on saidplate.

11. The clamp of claim 1 wherein the aperture of said clamping plate hasa major and a minor axis.

12. The clamp of claim 1 wherein at least a portion of the clampingplate adjacent the aperture and internal radially of said surfaceirregularities is debossed and the opposed surface adjacent the head iscomplementarily upraised.

13. A terminal clamp for removably securing and providing substantiallyidentical loads to wires of the same or differing diameters in thesecured position, said clamp comprising in combination:

a. a threaded shank having a head at one extremity and an entering endportion at the other extremity, said head being configured toaccommodate a tool for rotation of the threaded shank, said head havingan underhead surface having at least one integral,substantially-circular protrusion surrounding said shank intermediatethe inner and outer extremity, said shank having an annular collaradjacent but spaced from said underhead surface; and

b. a substantially rectilinear clamping plate having a substantiallycentrally-disposed aperture, said clamping plate being loosely andtiltably assembled on said shank between said head and said annularcollar, said plate having on the surface adjacent said head at least onesubstantially circular recess complementing in cross section theconfiguration -of said protrusion but having a larger diameter wherebythe extremity of .said protrusion registers being inclined away fromsaid head.

* IF I,

UNITED STATES PATENT OFFICE v CERTIFICATE OF CORRECTION Patent No. 3 744012 Dated July 3 1973 Inventofls) Charles E. Gutshall It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 2, line 27, change "tee" to -the;

Column 4, line 10, after "FIG. 7" insert -as indicated by the line 8-8of FIG. 6--';

Column 4 line 44 change "the" Second Occurrence to Column 5 line 31,change "upon" to --up on I Column 5 line 50 change "down-ward1y"- todownwardly--;

Column 7, line 35, change "surface".to -undersurface--;

- Column 7, line 51, change "inter-mediate" to -in'termediate;

Column 10, line 3, change "registratin" toregistration-.

Signed and sealed this 8th day of January 197A.

(SEAL) Attest: EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting OfficerI Acting Commissioner of Patents T. ARM P6 105 (10-69) USCOMWDC and, I

I 9 U GOVlIIillIT PRINTING OFIICI: "6 O-JG-ill

1. A teeter terminal clamp for removably securing the terminal portionof at least one conductor comprising in combination: a. a threaded shankhaving a head at one extremity and an entering end portion at the otherextremity, said head being configured to cooperate with a tool wherebythe shank may be rotated into or out of a threaded aperture, said headhaving an underhead surface having at least one, integral, substantiallyV-shaped, substantially-circular protrusion concentric with the shankaxis and inter-mediate the inner and outer extremities of the underheadsurface; b. a clamping plate substantially centrally apertured toloosely and teeterably receive said shank, said plate having on one sidethereof at least one substantially V-shaped, substantially circularrecess complementing said V-shaped protrusion but having a largerdiameter whereby the extremity of said V-shaped protrusion registerswith the inner wall of said recess intermediate the two extremitiesthereof when said protrusion and said recess are concentrically aligned,sAid plate having wire-engaging, anti-slip surface irregularities on theopposite side thereof; and c. means for retaining said plate on saidshank spacedly adjacent said head.
 2. The clamp of claim 1 wherein saidmeans for retaining said plate comprises an integrally-formed annularcollar spaced from said head sufficiently to accommodate said clampingplate in loose relationship prior to tightening.
 3. The clamp of claim 1wherein said means for retaining said plate comprises a nut threaded onsaid shank.
 4. The clamp of claim 3 wherein said plate has at least twoopposed appendages extending from margins thereof away from said headand substantially aligned with the axis of the shank.
 5. The clamp ofclaim 1 wherein said wire-engaging, anti-slip surface irregularitiescomprise grooves having at least portions disposed to intersect the wirebeing clamped substantially transversely.
 6. The clamp of claim 1wherein said wire-engaging, anti-slip surface irregularities compriseembossments disposed to intersect at least a portion of the wire beingclamped substantially transversely.
 7. The clamp of claim 1 wherein saidclamping plate is substantially rectilinear.
 8. The clamp of claim 7wherein said wire-engaging, anti-slip surface irregularities compriseintersecting embossments spacedly adjacent each of the four corners ofthe clamping plate substantially perpendicular to the sides thereof. 9.The clamp of claim 8 wherein outer corner portions intermediate saidembossments are inclined away from said head.
 10. The clamp of claim 1including a plurality of said protrusions on the underhead surface inspaced concentric relationship and a plurality of complementary recessesin spaced concentric relationship on said plate.
 11. The clamp of claim1 wherein the aperture of said clamping plate has a major and a minoraxis.
 12. The clamp of claim 1 wherein at least a portion of theclamping plate adjacent the aperture and internal radially of saidsurface irregularities is debossed and the opposed surface adjacent thehead is complementarily upraised.
 13. A terminal clamp for removablysecuring and providing substantially identical loads to wires of thesame or differing diameters in the secured position, said clampcomprising in combination: a. a threaded shank having a head at oneextremity and an entering end portion at the other extremity, said headbeing configured to accommodate a tool for rotation of the threadedshank, said head having an underhead surface having at least oneintegral, substantially-circular protrusion surrounding said shankintermediate the inner and outer extremity, said shank having an annularcollar adjacent but spaced from said underhead surface; and b. asubstantially rectilinear clamping plate having a substantiallycentrally-disposed aperture, said clamping plate being loosely andtiltably assembled on said shank between said head and said annularcollar, said plate having on the surface adjacent said head at least onesubstantially circular recess complementing in cross section theconfiguration of said protrusion but having a larger diameter wherebythe extremity of said protrusion registers with the inner wall of saidrecess intermediate the two extremities thereof when said protrusion andsaid recess are in registratin, said plate having on the opposite sidethereof wire-engaging, anti-slip embossments disposed to intersect thewire being clamped substantially transversely, said embossments beingspacedly adjacent each of the four corners and perpendicular to thesides thereof, outer corner portions intermediate said embossments beinginclined away from said head.